Case report forms (CRFs) are used to collect information from subjects in clinical studies. To facilitate analysis, CRFs are stored electronically. The CRFs may be initially recorded on an originating document (e.g., paper form, printout from clinical instruments, and so on) and then entered into an Electronic Data Capture (EDC) system. For quality control purposes, CRFs in the EDC system are subject to source verification, in which monitoring personnel compare a CRF in the EDC with the CRF's originating document to verify that the CRF is accurate. As clinical studies grow in size, with more subjects and forms, it is becoming increasingly difficult to perform source verification.